1)x^2-5x=0
x(x-5)=0
x=0 x=5
2)x^2+2x//x+4=8//x+4
x^2+2x-8=0
x=-4 x=2
3)10//x=7-x
10=7x-x^2
x^2- 7x +10=0
x=2 x=5